As we have promised you earlier, we are going to do a series of individual articles on the three Ancient Weapons from Eiichiro Oda’s One Piece series. In these individual articles, we are going to present each of the Ancient Weapons in more detail, revealing everything that is known about each of them. Our core article revealed only the basic details of the three Ancient Weapons and their powers and abilities, but in this series of articles, we are going to tell you everything that is known about these weapons, as well as everything we know.
In this article, we are going to present the Ancient Weapon Poseidon, the only currently confirmed living weapon among the three Ancient Weapons in One Piece.
Who is the Ancient Weapon Poseidon?
Poseidon was first mentioned when Nico Robin read Skypiea’s poneglyph. Recently, the king of the Ryugu Kingdom, Neptune, revealed that Poseidon is located on Fish-Man Island itself. This weapon is not an object, but a hereditary ability that only some female members of the royal family of Fish-Man Island develop every 100 years according to Neptune himself.
A power inherited and awakened by Princess Shirahoshi, which consists of being able to summon, communicate and control the sea kings at will. The only mermaid princess who has also possessed this ability is Princess Poseidon, who lived in the Void Century. Instead of being an inanimate object like the usual weapons (except for weapons attached to Devil Fruits), Poseidon is a mermaid who belongs to the royal bloodline of the Ryugu Kingdom.
After her death, her name was treated as a title given to a mermaid who was born into the royal family and had the same power that she possessed in life. In the present day, Shirahoshi has inherited Poseidon’s power and name from her. Any possessor of this ability is called Mermaid Princess. Poseidon has the power to communicate with and control sea kings, an ability that even the mightiest of merfolk cannot use.
What are the powers of the Ancient Weapon Poseidon?
Poseidon is one of the three Ancient Weapons, along with Uranus and Pluton, the latter possessing equal power and being capable of destroying entire islands. Poseidon is a mermaid born every millennium or two, with the power to control and communicate with the Sea Kings. This power is considered a weapon since Sea Kings are so powerful that they can destroy islands single-handedly just for food.
However, used for benevolent purposes, this power can save thousands of lives as Shirahoshi uses it to save the Fish-Men from Noah’s downfall. Shirahoshi is the heir to this fantastic power and awakened it during the fight between Luffy and Hody. She used it for the first time in an unconscious way to save her mother, Queen Otohime, threatened by a Celestial Dragon, by calling the Kings of the Seas.
According to Otohime, the legend adds that Shirahoshi will receive a visit from an unknown person responsible for guiding his power on the right path, and it is at this time that the world will experience profound upheavals.
How was the Ancient Weapon Poseidon created?
Poseidon lived during the Void Century and made a pact with Joy Boy. She would use her powers to command the Sea Kings to bring the Noah to the surface and activate its intended mission, details of which would be revealed when she was moved. However, Joy Boy failed to commit her to Poseidon for unknown reasons.
After this, Joy Boy left her act in a letter of apology located in the Poneglyph of the Gyojin Island, exactly in the Marine Forest of the Kingdom of Ryugu. After the Void Century, Poseidon disappeared from the records, with the only information available about her being the Shandora Poneglyph on Skypiea and the Fish-Man Island Poneglyph located in the Sea Forest, which is written as a letter of apology from Joy Boy to Poseidon, apologizing for breaking his end of the bargain.
Even after her death, her power did not die, and Poseidon’s ability was passed down through the generations of the royal family, though he never awoke. Meanwhile, Fish-Man Island tried to keep their end of the bargain despite Joy Boy not keeping hers. The World Government spent the next few centuries trying to prevent the awakening of the ancient weapons by banning the reading of the poneglyphs.
Poseidon’s story became a legend within Fish-Man Island over time, and stories were passed throughout the royal family of the Ryugu Kingdom. According to such a legend, a mermaid would be born with the ability to control the kings of the sea, on that day a man would come to guide her. The first Vander Decken traveled to Fish-Man Island to find this mermaid.
However, he failed to find her and the story is passed down from father to son, so each new Vander Decken tries to find the princess. Eight years prior to the start of the series, Princess Shirahoshi had unwittingly demonstrated the ability to summon Sea Kings when her mother was in danger of being shot by the world noble Mjosgard. Her screams summoned a group of the Sea Kings, allowing her mother and Vander Decken IX to find out about her ability.
At this point, Decken deduces that Shirahoshi is the Mermaid Princess of legend that his family had been searching for and decided to marry her to access her fearsome abilities (as well as her unparalleled beauty), prompting him to send his marriage proposals to her. threatening marriage for the next ten years. Otohime, knowing that such powers can be both beneficial and deadly, had to ask her three sons to train hard to become strong warriors in order to protect Shirahoshi when the time came.
Shirahoshi’s power was fully awakened during the fight against the New Fish-Man Pirates, which Neptune pointed out saying was not a good thing. In fact, when Caribou overheard Nico Robin and King Neptune discussing the ancient weapons and Shirahoshi as Poseidon, he quickly tried to kidnap her for her doomsday power, however, he was stopped by the Straw Hats.